son of security blogger, Karl Kraft, has shown him how to turn on the passcode lock and disable SMS Preview on his iPhone in order to prevent his parents from seeing any messages.
The 12-year-old uses his iPhone mostly for texting with his girlfriend and has discovered what looks like a new vulnerability with the device. Using those settings, the display of incoming text messages is blocked and shows an alert saying "New Text Message" even if an SMS comes through while the phone is locked. Using the emergency mode the text is displayed for all to see.
All Kraft needs to do if he wants to intercept the messages from his son’s bird is to steal the phone, place it in emergency mode and wait 30 seconds for the next sickly sweet message. Why any parent would want to do this is a matter for parent counselors to work out, but it does highlight another problem with the iPhone.
Another security hole related to password-protected iPhones was discovered in August, and last month a researcher disclosed that the iPhone captures all the activities of a user in order to enable the fading applications effect.
Check it out here